I, i, L, l, 1, 7, j, o, O, 0, D, G, C All have characteristics that set them apart from potential lookalikes - the bar through the 0 is one excellent example -

I, i, L, l, 1, 7, j, o, O, 0, D, G, C All have characteristics that set them apart from potential lookalikes - the bar through the 0 is one excellent example - but it’s up to the font designers to take readability into account, and most designers are looking at reading English prose, not code. They don’t think “my font might be used to render a URL in a context where a user will need to make an essential security decision based on whether the string they’re reading contains an l or an I.